The screen door of the invention in its preferred embodiment is of the sliding type, and it is equipped with rollers mounted in channels in the upper and lower edges of respective bonnets which are fitted over the top and bottom of the frame of the door. The rollers are received on rails which are fitted at the top and bottom of the doorway in which the door is to be installed.
Since the doorways do not have standard heights, it is usual in the prior art to provide the aforesaid bonnets at the top or bottom, or both, of the door frame, the bonnets being set to a desired displacement with respect to the frame, so that the rollers will fit exactly on the upper and lower rails. However, difficulties have been encountered in the prior art in providing a suitable means for locking the bonnets in a non-slipping relationship with the door frame after they have been set.
The present invention provides a simple and inexpensive assembly which can be loosened to permit the bonnets to be moved in or out to a desired displacement with respect to the door frame, and which may then be tightened to lock the bonnets to the frame without any tendency for the bonnets to slip, and which also serves to lock the corners of the door frame firmly together.
As explained above, the assembly comprises a serrated corner lock member which is fitted in a friction fit within the door frame at the adjacent corner of the door frame to hold the door frame together. The corner lock member includes an integral bushing which fits in the door frame between aligned holes. The assembly also includes a sex bolt (which comprises a headed sleeve with internal threads and an externally threaded bolt) which is received in the sleeve. Each bonnet has slots at each end which receive the sex bolt, and which permit the bonnet to be moved in or out with respect to the door frame. When the sex bolt is tightened, the corner lock member, the door, frame and the bonnet all lock together in a non-slipping relationship.